Work on rewards-based training! Teach them to word "down" for example, and give them a treat when they get down. With some cats, a spritz of water when they jump up will annoy them into not thinking it is a fun thing. Do they have cat trees, and places that it is okay for them to climb?

I sadly have found it almost impossible to stop my Found Hotel Cats from climbing.
My Empress is a climber and I have the feeling that she is giving Jo Jo lessons as he was up on a door ledge.
Thank God Kittens are tough!!!

Do they have their own furniture to climb up on? I found when I bought my cats their own furniture to scratch and play on... and "rewarded" them for using it (also apply a liberal amount of catnip to the "ok" areas), they tended to leave my stuff alone.

If they like being up high, perhaps you can look into buying or building a tall cat tree?

In my experiences, kittens tend to have more tendency to climb than when they grow older. I couldn't keep Voltron off anything when he was a kitten; now he's maybe 1 1/2 years old and he doesn't have that "wild" energy anymore so he's calmed down quite a bit.

My cat Badd @$$ Buddy loves to be up high. That's what cats do. It's an escape for him. You can try putting aluminum foil on the counters. Seriously, I don't know what the big deal is.

You need to get him his own TALL cat tree and spray it with catnip spray. It used to bother me when they climbed up on the counter. But not anymore. Like Katladyd said, it's their house too.

You can try a squirt bottle. Just don't squirt them in the face. Aim for their body. Life's too short to let that kind of stuff bother you.

Rest In Peace Casey (Bubba Dude) Your paw print will remain on my heart forever. 12/02
Mollie Rose, you were there for me through good times and in bad, from the beginning.Your passing will leave a hole in my heart.We will be together "One Fine Day". 1994-2009
MooShoo,you left me too soon.I wasn't ready.Know that you were my soulmate and have left me broken hearted.I loved you like no other. 1999 - 2010See you again "ONE FINE DAY"
Maya Linn, my heart is broken. The day your beautiful blue eyes went blind was the worst day of my life.I only wish I could've done something.I'll miss your "premium" purr and our little "conversations". 1997-2013 See you again "ONE FINE DAY"

We have that problem too. So many mornings I have woken up to the curtains being torn down because my frisky kittens thought it would be fun. Usually I keep a spray bottle of water at hand, I don't even have to squirt any more, they see the bottle and stop what they are doing. They just need a reminder every so often.